Abstract
The heights and widths of zinc dendrites were measured in pure zinc chloride solutions in the concentration and pH range prevailing in zinc-halogen load leveling batteries. At constant overpotential the height increases linearly with time, indicating a constant growth rate. The higher the concentration and the overpotential, the faster is the growth. The critical overpotential for initiation of dendrite growth is 14 mV independent on the concentration. The growth rate increases when the pH decreases. The influence of hydrogen gas evolved at low pH on the growth rate is discussed. Propagation rate is discussed in terms of an extended Barton-Bockris model. When the height of the dendrite is smaller than the diffusion layer thickness, mass transport to the tip is linear and the dendrite propagates in an exponential manner. When the height is larger than the diffusion layer, mass transport to the tip is spherical and the propagation is linear with time. At constant overpotential the widht is a linear function of the square root of the height, indicating that the dendrite has a shape which is preserved during the growth and the tip radius is maintained constant as predicted by the theory.
| Original language | English |
|---|---|
| Pages (from-to) | 739-748 |
| Number of pages | 10 |
| Journal | Electrochimica Acta |
| Volume | 27 |
| Issue number | 6 |
| DOIs | |
| State | Published - 1 Jan 1982 |
| Externally published | Yes |
ASJC Scopus subject areas
- General Chemical Engineering
- Electrochemistry